The present invention broadly relates to firing mechanisms, and, in particular, concerns a new and improved construction of a firing mechanism for an automatic firing weapon.
Generally speaking, the firing mechanism for an automatic firing weapon of the present development is of the type comprising a breechblock provided with a catch surface and the underside of which breechblock serves as a control or camming surface for controlling the firing mechanism. There is also provided a spring-loaded catch pawl or detent which is pivotably mounted in a firing mechanism housing. The catch pawl or detent, when in its breechblock catch position, protrudes into the path of travel of the breechblock. There is also provided a firing or trigger lever which can be actuated by a firing or trigger table or equivalent structure. This firing or trigger lever serves for pivoting the catch pawl out of its breechblock catch position into a breechblock release position. A feeler or sensor lever is provided, which is pivotable by the action of the underside of the breechblock out of a locking position for the firing lever into a release position for such firing lever.
According to a state-of-the-art firing mechanism of the aforementioned type, as disclosed in German Pat. No. 3,103,864, published Sept. 2, 1982, the breechblock of the firing weapon is equipped with a catch shoulder and a control surface coacting with this firing mechanism. Such firing mechanism is arranged within a housing and possesses a first control lever with can be actuated by a firing table. There is also provided a second control lever which can be actuated by the control surface of the breechblock body. Additionally, there is provided a catch pawl which can be pivoted or rocked into the path of movement of the catch shoulder. This catch pawl can be actuated by both of the aforementioned control levers. The second control lever, constituting a release lever, is pivotably arranged at a holder lever. This holder lever is mounted to be pivotable, against the force of a holding or retaining spring, about a pivot shaft which is fixed in the housing. A nose member of the holder lever retains the catch pawl in a first clearly defined intermediate position which only can be released by the action of the body of the breechblock. The first control lever is pivotably mounted as a firing lever in the housing and a stop lever for the catch pawl is displaceably arranged at such firing lever. The catch pawl possesses at its rear end, above a stop surface which coacts with the stop lever, a concave surface for the deflective contact with the stop lever in a second intermediate position. The holder lever can be deflected or moved in counterclockwise direction by the body of the breechblock through the action of the release lever, in order to release the catch pawl from the first intermediate position.
This heretofore known firing mechanism essentially solves the same objectives as the present invention, namely prevents damage of the catch surface at the breechblock and the impact or stop surface at the catch pawl. Such damage can arise when there occurs impact of the breechblock against the catch pawl before the catch pawl has completely reached its breechblock catch position. The breechblock only should be caught during such time as there is present a full area or surface impact of its catch surface against the impact or stop surface of the catch pawl.
It is to be appreciated, however, that the aforementioned prior art firing mechanism fulfills such object in a completely different manner.
1. The mode of operation of the known firing mechanism is exactly the converse of that of the present invention. With the control surface of the breechblock there is brought about a release of the catch pawl for enabling its pivoting into the breechblock catch position. In contrast thereto, the invention contemplates that with the control surface of the breechblock there is prevented release of the catch pawl for pivoting into the breechblock catch position.
2. The control lever of the prior art firing mechanism is pivotably arranged at a holder lever and the stop lever of the known firing mechanism is pivotably arranged upon the firing lever. In contrast thereto, the invention contemplates that all levers or lever members are pivotably mounted about housing-fixed shafts, or, stated in a different manner, all of the pivot shafts are secured in the housing of the firing mechanism.
3. The release lever of the prior art firing mechanism impacts by means of a relatively pronounced rounded nose member or nose against the control surface of the breechblock. In contrast thereto, the feeler or sensing lever of the inventive firing mechanism impacts by means of a feeler surface which is inclined with respect to the path of movement of the breechblock against the control or camming surface of the breechblock.
Moreover, the aforementioned state-of-the-art firing mechanism has the following drawbacks:
1. The elements which are pivotably mounted upon pivotable levers constitute a disturbance-prone construction of the firing mechanism, particularly when confronted with the pronounced vibrations of the firing weapon, typically a cannon.
2. The impact of the breechblock against the markedly or pronouncedly rounded nose or nose member of the release lever results in considerable wear.